The present invention relates generally to plasma cutting systems and other high power output welding-type systems such as welding and induction heating systems and, more particularly, to a temperature indicating consumable for use with such systems.
Plasma cutting is a process in which an electric arc is used to cut a workpiece. Plasma cutters typically include a power source, an air supply, and a torch. The torch, or plasma torch, is used to create and maintain the plasma arc that performs the cutting. A plasma cutting power source receives an input voltage from a transmission power line or generator and provides an output voltage to a pair of output terminals, one of which is connected to an electrode and the other of which is connected to the workpiece.
An air supply is used with most plasma cutters to help start the arc, provide the plasma gas to the torch, and cool the torch. A movable or fixed electrode or consumable serves as a cathode and a fixed nozzle serves as an anode. The air supply moves the electrode and as the electrode moves away from the nozzle, it opens the nozzle, and a plasma jet is created. The plasma jet causes the arc to transfer to the work piece, and thus initiates the cutting process. In other plasma cutting systems, a high frequency starter is used to initiate the cutting process.
During the cutting process, as the arc transfers on the plasma from the electrode to the workpiece, heat is generated. The amount of heat generated during operation is partially determined by the type of material being worked, the power output required to work the material, and the type of consumable required to effectuate the desired work. Operating the torch at increased temperatures can effectively shorten the working life of a consumable, and if not addressed, can result in damage to the torch body and/or the power source. Additionally, plasma cutting with an overheated consumable also results in poor cut quality.
It would therefore be desirable to design a consumable which indicates an operating temperature of the consumable.